Lack of epithelial PPARγ causes cystic adenomatoid malformations in mouse fetal lung

Biochem Biophys Res Commun. 2017 Sep 16;491(2):271-276. doi: 10.1016/j.bbrc.2017.07.113. Epub 2017 Jul 21.

Abstract

Peroxisome proliferator-activated receptor-γ (PPARγ) plays an important role in lipid and glucose metabolism. In this study, the function of PPARγ on lung development was investigated. Lung-specific Pparg conditional knockout mice (PpargΔLuEpC) were developed using Cre-Lox system. PpargΔLuEpC mice showed abnormal lung development with enlarged airspaces and followed by increase of apoptotic cells at E14.5 to E18.5. Gene analysis revealed that expression of Pmaip1, a gene related to apoptosis, was significantly increased while expression of Retnla, a gene related to anti-apoptosis, was dramatically decreased in the fetal lung (E14.5) of PpargΔLuEpC mice. In addition, expression of Pthlh, a gene phenotypically expressed in the congenital cystic adenomatoid malformation (CCAM), was increased at E14.5 to E18.5 in the lung of PpargΔLuEpC mice. Cell culture studies revealed that PPARγ could bind to promoter region of Pthlh gene as a repressor in the immortalized mouse lung epithelial cell line MLE-15. Surprisingly, phenotypic changes in MLE-15-shPparg cells, stably transfected with shPparg plasmid, were similar to the PpargΔLuEpC mice model. In addition, MLE-15-shPparg cells were easily detached from the cultured plate when cold phosphate buffered saline was applied. Furthermore, expression of Cdh1, a gene related to cell adhesion, was significantly reduced in the MLE-15-shPparg cells. Taken together, PPARγ may play an important role in fetal lung development via alveolar cell-to-cell adhesion system.

Keywords: Cystic adenomatoid malformation; PPARγ.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Binding Sites
  • Cdh1 Proteins / genetics
  • Cdh1 Proteins / metabolism
  • Cell Adhesion
  • Cell Line, Transformed
  • Cystic Adenomatoid Malformation of Lung, Congenital / genetics*
  • Cystic Adenomatoid Malformation of Lung, Congenital / metabolism
  • Cystic Adenomatoid Malformation of Lung, Congenital / pathology
  • Embryo, Mammalian
  • Epithelial Cells / metabolism*
  • Epithelial Cells / pathology
  • Fetus
  • Gene Expression Regulation, Developmental*
  • Genes, Reporter
  • Intercellular Signaling Peptides and Proteins / genetics*
  • Intercellular Signaling Peptides and Proteins / metabolism
  • Luciferases / genetics
  • Luciferases / metabolism
  • Lung / metabolism
  • Lung / pathology
  • Mice
  • Mice, Knockout
  • PPAR gamma / deficiency
  • PPAR gamma / genetics*
  • Parathyroid Hormone-Related Protein / genetics
  • Parathyroid Hormone-Related Protein / metabolism
  • Primary Cell Culture
  • Promoter Regions, Genetic
  • Protein Binding
  • Proto-Oncogene Proteins c-bcl-2 / genetics*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Respiratory Mucosa / metabolism
  • Respiratory Mucosa / pathology
  • Signal Transduction

Substances

  • Cdh1 Proteins
  • Fzr1 protein, mouse
  • Intercellular Signaling Peptides and Proteins
  • PPAR gamma
  • Parathyroid Hormone-Related Protein
  • Pmaip1 protein, mouse
  • Proto-Oncogene Proteins c-bcl-2
  • Retnla protein, mouse
  • Luciferases